Television apparatus



XE 2,077,365. I

April 20, 1937. A. ZILLGER TELEVISION APPARATUS Filed Aug, 10,1952 2Sheets-Sheet 1 'INVENTOR /P/w Z/LLER ATTORNEY n'm'aae 08 CLASSIF;

April 1937- A. ZILLGER 2,077, 866

TELEVI S I ON APPARATUS Filed Aug. 10, 1932 2 Sheets-Sheet 2 INVENTORARA/0 Z/LAGER ATTORNEY Patented Apr. 20, 1937 UNITED STATES TELEVISIONAPPARATUS Arno Zillger, Narberth,

Pa., assignor, by mesne assignments, to National Television Corporation,Wilmington, Del., a corporation of Delaware Application August 10,

8 Claims.

This invention relates to television apparatus and particularly to ascanning device to be used therewith.

One of the objects of the invention is to pro- 5 vide a scanning devicefor a television apparatus which operates by reflection.

Another object of the invention is to provide a reflecting scanningdevice in which the effect of the operating light upon any surfaces ofthe 10 device other than those doing the actual scanning, is notdeleterious to the production of accurate images.

Still another object of the invention is to provide a reflectingscanning device in which all 5 surfaces other than the active surfacesreflect light away from the observer.

Other objects and objects relating particularly to the construction andassembly of the various parts will be apparent as the description of theinvention proceeds.

Several embodiments of the invention have been illustrated in theaccompanying drawings, in which:

Fig. 1 is a side elevational view of a receiving 25 television apparatusembodying the invention;

Fig. 2 is a sectional plan view of the drum taken on the line 2- 2 ofFig. 1;

Fig. 3 is an enlarged sectional plan view of a portion of the drum;

Fig. 4. is a sectional elevational view taken on the line 44 of Fig. 3;

Fig. 5 is a perspective View of one of the plates of the drum;

Fig. 6 is a sectional end View through one of 35 the plates taken on theline d4 of Fig. 3 and shown with a modulated light source; and

Fig. '7 is a perspective View of another form of plate which may beused.

Referring now more specifically to the draw- 40 ings, a televisionreceiving apparatus is illustrated in Fig. 1 in which a light source IDhas an envelope consisting of two small bulbs H and I2 joined togetherat their tips or rounded ends by a relatively long tube IS. The bulbs lland 45 12, as well as the tube l3, may be made of glass,

quartz, or other transparent material used extensively for electric lampbulbs. The bulb H has an inturned press 14 which supports a cupshapedanode I5 mounted on a lead-in wire it,

50 while the bulb l2 has an inturned press I! which supports a cathode[8 upon a lead-in wire 19. The anode l5 may be formed of any desiredmetal, such as nickel, and the cathode I8 is preferably formed of a rollof nickel gauze although 55 other metals such as Swedish iron andtantalum 1932, Serial No. 628,159

may be used. A disc l5a of mica or other insulating material may bepositioned against the outer end of the anode 15, a short connecting rodlBa which may be welded to the anode passing through a hole in the disc.The support rod l6 may be welded to the rod lfia, thus supporting theanode and securing the disc in position. The disc may be large enough toalmost touch the walls of the bulb and tends to prevent discharge fromforming on the rod t6 adjacent the press.

The cathode I8 is preferably provided with as large a surface aspossible, and hence it may be formed of a roll of wire mesh 9 or 10inches long by about an inch wide. This strip of mesh is wound up andattached to a short support rod l9a which may be in turn welded to. thelead-in wire IS. A disc 18a similar to the disc l5a described above, maybe mounted on the rod Mia and held against the cathode by the supportrod I9. This disc prevents undue discharge on the rod l9 and heating ofthe press.

The lamp may be filled with an ionizable gas, such as neon, or mixturesof neon and mercury vapor maybe used with good results. The pressure ofthe gas may be in the neighborhood of mm. of mercury or under. When acurrent in the neighborhood of 100 milliamperes is allowed to flowthrough this lamp at a pressure of from 600 to 1500 volts, a dischargeoccurs between the anode l5 and the cathode l8 passing through thenarrow tube l2. This discharge is very intense and is easily modulatedwhile the color depends largely on the combination of gases used, themixture of neon and mercury vapor producing a bluish white light. Thislamp while extremely efiective in the apparatus to be described,actually forms no part of my invention. Other light sources whichproduce a line of light and which may be modulated in accordance with anincoming television signal may be used in place of the one justdescribed.

A radio receiving set 20 may have its output connected respectively bymeans of wires 2| and 22 to the lamp lead-in wires [9 and I9. Where adirect wire television system is used the radio receiving set would, ofcourse, be replaced by an amplifier.

In order to insure starting the lamp, I prefer to provide a high tensioncoil 23 having a secondary winding 24 and a primary winding 25 in serieswith a battery 26, a switch 21, and an interrupter 21a. The secondarywinding may be connected between the wires H and 22 by means of wires 28and 25! and a spark gap 30 may also be connected in series with thewinding to prevent the flow of the lamp operating current therethrough.In starting the lamp the switch Zl is momentarily depressed which causeshigh tension current to produce a discharge within the lamp which whenonce started will be maintained by the output of the radio set.

The present invention relatm particularly to the scanning device whichcomprises a drum 3| rotatably mounted on a vertical shaft 32 rotated bya motor 33 which is adapted to run in syn'. chrony with the speed of themotor running the transmission set. If the receiver is used on the samepower circuit as the transmitter, a synchronous motor will accomplishthis result, but if the circuit is different from that used by thesending apparatus, a suitable synchronizing device (not shown) should beused to keep the motor 33 running in synchrony with the motor of thetransmitting set.

The drum 3! comprises a plurality of plates 34 which may be maderectangular as indicated in Figs. 2 .and 5, and are each provided with acentral hole 35a to fit over the shaft 32 and a reflecting edge 35 whichmay lie in a plane perpendicuiar to the surface of the plates. These 7plates are arranged in a stack with the reflecting edge of eachsuccessive plate turned at a slight angle with respect to the platebeneath it so that the reflecting edges form a spiral around thecircumference of the drum, with equal angles between adjacent edges.Where an image is formed of sixty lines, as has been the usual practiceheretofore, it is necessary to provide sixty reflecting edges, and hencethere will be sixty plates and the angle between every two plates willbe six degrees (6) so that one com plete rotation of the drum willproduce one complete scanning of the image. This construction is shownand described in the patent to Gardner,

No. 1,753,697, wherein the other edges of the absorbing paint, there isstill some reflection from these surfaces which give rise to distortionof the image produced or at least detracts from its clarity. I havefound that this difficulty can be entirely eliminated by forming theother long edge 36 of each plate and the two ends 3'! and 38 in planeswhich are not parallel with the axis of the drum but lie at an anglewith the axis, so that the surfaces slope towards the axis at the lowerend of the drum, as clearly indicated in Figs. 1, 4, 5 and 6 of thedrawings. While it may be preferred to provide these other edges withreflecting surfaces'this is not absolutely necessary, butthey should atleast be smooth so as not to disperse the light falling upon them.

While the light rays from the line of light reflected by the surfaces 35of the plates are redirected to the eye of an observer who stands sothat his eye is about midway between the top and bottom of the drum, allof the other surfaces 36,

31, and 38 will reflect light downwardly as clear- 40 may rest on awasher 4! which in turn may rest on a shoulder 42 formed on the shaft 32while the upper bar 39 may be pressed down upon the plates by a washer43 and a nut M threaded on the end of the shaft.

It is very desirable that the plates be very accurately positioned withrespect to each other in order to get good results, and I have foundthat to depend on the pressure of the nut' is to hold them in positionhas disadvantages in that the plates tend to warp and so to distort theimage.

' I prefer to fasten each plate, with respect to angular movement aboutthe shaft, to the plate above and below it and to this end I provide apair of holes 45 and 45 in one end of each plate and a similar pair ofholes 31 and 38 in the other end. These holes are" on a circle about thecentral hole 3 3a and are spaced equally from the center line of theplate in such a manner that the angle formed with the center of theplate is 6. This angle would, of course, vary if more or less plateswere used, sixty. (60) being the number chosen for purposes ofillustration The plates are placed on the shaft one at a time, thesecond one being turned so that the hole 46 therein coincides with thehole 65 in the first plate and the hole 48 coincides with the hole 47 inthe first. A pin 49 is then inserted through the holes 46 and 65 in thesecond and first plate respectively and another through the holes 48 and47 in the second and first plate. These pins may be slightly shorterthan twice the thickness of one plate but are made to snugly fit theholes 2!! as to keep the plates perfectly positioned. The first platemay look with the bar 40 in the same manner as may also the upper platewith the bar 39.

The plates of the drumv have been described above as being rectangularin shape. The invention is not to be limited, however, to rectangularplates as any number of sides may be used as for instance the triangularplate 53 shown in Fig. '7, the edge 55 of which is perpendicular to thesurface of the plate and forms the active refleeting edge, while theedges 52 and 53 are formed at an angle so that they will reflect lightaway from the observer. The plates may also be formed with curvedinstead of straight edges, or

may be made like a disc with one flat edge and the rest in the form of acircle. This edge may also be formed at an angle so that any lightrefiected thereby will be directed away from the line of observation.

It will be seen from the above that I have provided a reflectingscanning device for a television apparatus by means of which the clarityof the image has been greatly improved as it eliminates any possibilityof extraneous light affecting the image.

In the drawings a receiving television apparatus is disclosed, but it isobvious that the scanning drum of the transmitting apparatus may besimilarly constructed and the invention is intended to cover bothsending and receiving devices.

Many modifications of the invention may be resorted to without departingfrom the spirit thereof, and I do not desire to limit myself to what hasbeen shown and described except as such limitations occur in theappended claims.

What I desire to claim is:

1. A television scanning device comprising a plurality of platesarranged in a stack and rotatable about the axis of said stack, one edgeonly of each plate being used for scanning a picture, said edge having ahigh reflecting surface at a uniform angle to the axis of said stack andadapted to form one line of the picture and the reflecting edges ofsuccessive plates being spaced angularly around the axis of said stack,all other edges of said plates being formed at a different angle to theaxis of said stack, said angle being such that light is directed fromsaid other edges outside the field of vision as defined by said highlyreflecting surfaces.

2 In a scanning drum for a television apparatus a plurality ofrectangular plates forming a helix completely about the axis of thedrum, ar-

ranged in a stack rotatable about the axis thereof, each of said plateshaving one long edge only adapted to be used for scanning a picture,said edge being highly polished and lying in a plane bearing the sameangular relation to the axis of said stack that the planes of the sameedges on all the other plates bear to said axis, and all the edges onsaid plates not functioning to produce a portion of the picture havingsuch relation to said axis that light is directed therefrom outside thefield of vision as defined by said highly polished edges.

3. In a scanning drum for a television apparatus, a plurality ofrectangular metal plates arranged in a stack and rotatable about theaxis thereof, one long edge only of each plate being used for scanning apicture, said edge being highly polished and lying in a plane having apredetermined angle with the axis of said plates, said plates being somounted that the reflecting edges thereof form a 360 helix around saiddrum with equal angular spacing therebetween, all edges of said platesnot functioning to produce a portion of the picture having such anangular relation with respect to said axis that light is directedtherefrom outside the field of vision as defined by said highly polishededges.

4. In a television receiving apparatus, a rotatable drum comprising aplurality of stacked plates forming a helix completely about the axis ofthe drum, each of said plates having one edge only to be used forscanning a picture, said edge being polished and having a predeterminedrelation to the axis of said drum and functioning to produce a portionof the picture and all edges which do not function to produce a portionof the picture having such a relation to said axis that light isdirected therefrom outside the field of vision as defined by saidpolished edges, and a long narrow light source spaced from said drum andsubstantially parallel to the axis thereof.

5. In a television receiving apparatus a rotatable drurn comprising "aplurality of stacked plates, each of said plates having one edge only tobe used for scanning a picture, said edge being polished and having apredetermined relation to the axis of said drum, said plates being sopositioned that the reflecting surfaces form a helix around said drumwith equal angular spacing, all other edges of said plates having suchan angular relation with respect to the axis of said drum that light isdirected therefrom outside the field of vision as defined by saidpolished edges, and a long narrow light source spaced from said drum andsubstantially parallel to the axis thereof.

6. A scanning drum for use in television comprising a plurality ofstacked plates, each plate having one edge only which is used forscanning a picture, such edge having a reflecting surface, the plane ofwhich bears a predetermined angle to the axis of said drum, and a secondreflecting edge on each plate having an angle to the axis of said drumsuch that light is directed therefrom outside the field of vision asdefined by said first mentioned reflecting surfaces, the number of saidplates being sufficient to permit formation of an optical image on saiddrum without the interposition of an optical system between the drum andthe point of observation.

'7 A scanning drum for television use comprising a plurality of platesarranged in a stack, one edge only of each plate being used for scanninga picture, said edge being reflecting and lying in a plane having apredetermined angle tothe axis of said drum and corresponding to oneline of a picture to be reproduced, and all other edges of said platesbeing also reflecting but lying in planes having an angle to said axissuch that light is directed therefrom outside the field of vision asdefined by said first mentioned reflecting edges, the reflecting edgeslying at said predetermined angles to the drum axis producing a 360helix.

8. A television scanning device comprising a rotating drum, a pluralityof reflecting surfaces on said drum arranged in a successive helixcompletely around the circumference thereof and in planes substantiallyparallel to the axis of said drum, there being one surface only used forscanning the picture, such surface forming one line of the picture, anda plurality of other reflecting surfaces arranged around thecircumference of said drum and. lying in planes which are at an angle tothe axis thereof, the angle being such that light is directed from saidsecond mentioned reflecting surfaces outside of the field of Vision asdefined by said first mentioned surfaces.

ARNO ZILLGER.

